Tooth Loss as a Risk Factor of Declining Intrinsic Capacity Domains in Later Life: Evidence From NHANES 2009-2014

Background: The World Health Organization (WHO) defined intrinsic capacity (IC) as the combination of physical and mental resources essential for healthy aging. Currently, the role of oral health in relation to IC remains underexplored. Objectives: To examine the associations among the number of remaining teeth and IC domains. Methods: From the 30 468 subjects of the National Health and Nutrition Examination Survey (NHANES) 2009–2014, we included 787 participants aged ≥ 60 years with available dental/IC-related data, representing a weighted population of approximately 8.35 million U.S. older adults. Dentition status was categorised into four groups: ≥ 20 teeth, 10–19 teeth, 1–9 teeth and edentulous. IC domains (locomotion, vitality, psychological well-being, sensory function and cognition) were operationalised using NHANES items aligned with WHO definitions. Results: Compared with participants with ≥ 20 teeth, those with 10–19 teeth had significantly higher odds of locomotion difficulty [adjusted-odds ratio (OR): 2.18; 95% confidence interval (CI): 1.30–3.66], participants with 1–9 teeth/edentulous also showed an increased risk of locomotion difficulty. The number of remaining teeth was also associated with reduced vitality, particularly unintentional weight loss and lower appetite. Edentulous participants had an increased risk of poor psychological well-being, including depressive symptoms (adjusted-OR: 1.91; 95% CI: 1.22–3.01) and anhedonia (adjusted-OR: 2.27; 95% CI: 1.22–4.24). Significant associations were also found between edentulism and sensory impairments, particularly hearing loss (adjusted-OR: 2.42; 95% CI: 1.17–4.99). Conclusion: The number of remaining teeth in older adults was significantly associated with impairments across multiple IC domains. In particular, reduced dentition (10–19 teeth, 1–9 teeth or edentulism) was consistently linked to impaired locomotion.